Filter bag



C R. SARE ETAL Nov. 8, 1960 FILTER BAG Filed Oct. 5]., 1958 INVENTORS CARL A. SARE y NORMAN Wl/m IKR United States Patent FILTER BAG Carl R. Sare, Shaker Heights, and Norman W. Hilliker,

Filed Oct. '31, 1958, Set. No. 770,963

'4 Claims. (Cl. 183-51) This invention relates to improvements in filter bags, particularly filter bags or dust bags for use in the dust chamber of a machine for separating dust from air or other gas. The bag of the present invention is intended as one of a series of vertically disposed bags mounted side-by-side in the dust chamber of a dust collector, for example, a machine of the general character of that illustrated in Boesger Patents 1,868,876 and 2,695,681.

The present machine has to do with taking the dust out of air or other gas, and does not concern itself with the intermittent cleaning of the bags as by shaking them or passing air through them in a reverse direction. The invention is in the nature of an improvement on certain features of the application, Serial No. 692,778 of Allen H. Jones, filed October 28, 1957, now Patent No. 2,906,- 371, issued Sept. 29, 1959.

-In accordance with the latter invention, each filtering element comprises two compartments, a forward compartment which performs the dust separating function, and a rear compartment which is attached to but separate from the forward compartment and is narrow, but is elongated vertically for receiving a rear mullion which is rigid and which when pulled rearwardly supports the bag and tensions it. The forward compartment of the bag may be provided with internal spacers 9 to prevent the side walls of each bag from collapsing under suction. No spacers are needed for the rear compartment because that compartment is not subjected to suction from the clean air chamber.

One of the objects of the invention is the provision of a two-compartment bag so constructed that it may be formed from a single piece or strip of cloth.

Other objects and features of novelty will appear as we proceed with the description of that embodiment of the invention which, for the purposes of the present application, we have illustrated in the accompanying drawing, in which:

Fig. 1 is a side elevation view of a bag embodying the invention;

Fig. 2 is a rear end view of the bag;

Fig. 3 is a front end view;

Fig. 4 is a fragmental horizontal sectional view, on a larger scale, the view being taken substantially on the line 44 of Fig. 1 with the rear mullion and other metal parts removed;

Fig. 5 is a sectional view on the same scale as Fig. 4, but including the rear mullion and the metal connections for supporting and tensioning the bag;

Fig. 6 is a fragmental sectional view on the line 6-6 of Fig. l but showing the parts on a larger scale; and

Fig. 7 is a fragmental sectional view taken substantially on the line 77 of Fig. 1 with the parts on a larger scale.

The bag of the present invention has a forward dust removing or separating compartment which may or may not be sectionalized, and a rear compartment that has no dust removing function but serves to hold a rear rigid mullion which, when the bag is in use, is drawn rearwardly for supporting and tensioning the bag. In the present instance the bag is formed of a single piece or length of cloth which is folded transversely to provide side walls. The upper and lower edges of these walls are sewed together to form a forward compartment that is open at the front where it joins the dust wall, the forward edges of each bag being secured to the dust wall around a vertically elongated opening or slot through the wall. The rear end of the bag is folded and sewed in a novel and peculiar manner to form a separate compartment at the rear of the bag, as will now appear.

The length of cloth from which the bag is made is of a Width that is substantially the same as the height of the bag. This cloth may be said to extend from the front end of the bag rearwardly to form one wall 10 of a single thickness extending back to the juncture of the front and rear compartments. It then extends back a short distance further to form the outer side wall portion 11 of the rear compartment, then inwardly to form a rear wall portion 12, and then rearwardly and outwardly to form a double or rebent portion 13, 14, then outwardly to form a wall.

15 that runs along and adjacent to the rear wall portion 12, then forward as indicated at 16 which makes, with the portion 11, a double thickness wall 11, 16. The two portions of this double thickness wall are sewed together by a vertical line of stitching 17 running from the top to the bottom of the bag. The cloth then extends transversely as a wall 18 of single thickness over to the other side of the bag. The wall 18 is a separating wall between the two main compartments of the bag, that is the forward dust separating compartment 19 and the rear mullion holding compartment 2i). The cloth of the bag then extends rearwardly to form the inner wall 21 of one side of the rear compartment, then inwardly to form one thickness 22 of a part of the rear wall, after which it is doubled back to form a two-thickness fold 23, 24. The redoubled folds 13, 14 and 23, 24 are now sewed together by two rows of stitching 25, 26 extending the full height of the bag so as to close the rear edge of the rear compartment and, incidentally the rear edge of the bag, the cloth next being folded outwardly to constitute a second rear thickness 27 and forwardly to constitute a second side thickness 28. The two thicknesses 21, 28 are then sewed together by a vertical line of stitching 29 which completes the vertical walls of the rear compartment'ZO. The remaining portion of the cloth is then carried forward to form the other side wall 30 of the forward compartment of the bag.

To make the seams at the top and bottom edges of the bag the cloth of one wall is preferably folded in a U shape in cross section as shown at 31 and 32 in Figs. 6 and 7, the other wall being received between the walls of the U fold and stitched together as indicated at 33 and 34 to form upper and lower seams 35 and 36. The seams 35 and 36 in front of the dividing wall 18 connect single thicknesses of cloth, but the corresponding seams 37 and 38 to the rear of the wall 18 connect doubled thicknesses of cloth.

Within the rear compartment 20 we mount a rigid mullion which we prefer to be a metal mullion 40 of steel or other rigid metal of substantially the same length as the height of the bag. The rear seam of compartment 20 is omitted for a distance, as indicated at 41, at the bottom of the bag in order to permit the mullion to be inserted into the compartment. Somewhere near the middle of the mullion there is mounted a hook 42 which is caused to extend rearwardly through a slit 43 in the rear seam. The hook 42 is caused to engage an eye bolt 44 which extends through a hole in one flange 45 of an angle iron 46 that is fixedly mounted in the dust chamber of the dust collector. To the rear of the flange 45 the shank of the eye bolt is preferably surrounded by a coil spring 47 which bears against a washer and nut 48 and 49 on the eye bolt. The bag carried by the mullion is thereby placed under tension and the rear end of the bag is supported.

In addition to the hook 42 carried by the mullion near its center point the mullion also carries a pin 5% which is fixed in the mullion near its lower end thereof. The stitching 25, 26 at the bottom of compartment 20 is interrupted for a short distance to permit mullion 40 to be inserted upwardly into the compartment. The pin 56, which is of appreciable length, does not enter the compartment 20, but projects rearwardly through the opened seam at the bottom of the compartment. The function of pin 50 is to hold the mullion, and hence the bag, from sidewise tilt around the hook 42. The front-to-back dimensions of the rear compartment 2d are such that the mullion 40 and its hook 42 can be inserted into the compartment in the manner indicated in dot-and-dash lines in Fig. 1, after which the hook 42 may be caused to projec rearwardly through the slit 43 before the hook is caused to engage the eye bolt 44, when the bag will be ready for operation.

The bag may be advantageously sectionalized by horizontal seams 52 and 53 for a purpose explained in the aforesaid Jones application, Serial No. 692,778. The front end of the bag is formed with side flaps 54 and 55 which may have wire reenforcements 56 and 57. At the top and bottom the side flaps 54 and 55 may be joined by the strips 58 and 59 of the same material as the bag proper. Small holes 60 may be formed in the two side flaps 54 and 55 and in the end strips 58 and 59 for attaching the front end of each bag to the dust wall, not shown.

Having thus described our invention, we claim:

1. A fabric filter bag for a machine for separating dust from air or other gases, said bag having opposed sides joined along corresponding opposed edges to provide a bag open at one end only, said bag having a bottom end opposite to the open end and scams along the bottom end providing a separate elongated mullion compartment extending the extent of the bottom end, the fabric of said bag extending outwardly of the bottom end thereof to provide the walls of said compartment and closing the ends of said elongated mullion compartment and the sides thereof extending in a direction parallel to the direction in which said bottom end extends whereby said mullion con1- partment is closed on all sides and ends, said mullion compartment having a slit-like opening in one wall thereof to accommodate the insertion of a mullion and a further opening therein for accommodating connecting means extending outwardly from the mullion in the mullion compartment in a direction away from the open end of the bag.

2. A filter bag as defined in claim 1 wherein a single piece of fabric constitutes the sides of said bag including the mullion compartment thereof, said fabric being reversibly folded on itself along the bottom end of the bag to provide the bag bottom and flange-like portions extending outwardly from the bottom of the bag away from the open end thereof with said portions being joined at their outer ends by a seam which extends substantially the extent of the bottom end of the bag to provide said mullion compartment, said seam being interrupted adjacent one end thereof to provide said slit-like opening and adjacent the central portion thereof to provide said further opening.

3. A fabric filter bag for a machine for separating dust from air or other gases, said bag having opposed sides joined along corresponding opposed edges to provide a bag open at one end only, said bag having a bottom end opposite to the open end and seams along the bottom end providing a separate elongated mullion compartment extending the extent of the bottom end, the fabric of said bag extending outwardly of the bottom end thereof to provide the walls of said compartment and closing the ends of said elongated mullion compartment and the sides thereof extending in a direction parallel to the direction in which said bottom end extends whereby said mullion compartment is closed on all sides and ends, a mullion in said mullion compartment and extending substantially the extent of the bottom end, a connecting means extending outwardly from said mullion in the direction away from the open end of the bag, said separate compartment having a wall adjacent the side of said mullion facing away from said one end and an opening in said wall for passing said connecting means, said wall having an opening therein adjacent one end of said mullion for accommodating the insertion of the latter and disposed in the wall whereby said side of said mullion covers the opening after the insertion of the mullion.

4. A filter bag as defined in claim 3 wherein a single piece of fabric constitutes the sides of said bag including the mullion compartment thereof, said fabric being reversibly folded on itself along the bottom end of the bag to provide the bag bottom and flange-like portions extending outwardly from the bottom of the bag away from the open end thereof with said portions being joined at their outer ends by a seam which extends substantially the extent of the bottom ends of the bag to provide said mullion compartment, said seam being interrupted adjacent one end thereof to provide said slit-like opening and adjacent the central portion thereof to provide said further opening.

References Cited in the file of this patent UNITED STATES PATENTS 1,496,666 Fatscher June 3, 1924 2,314,830 Hunter Mar. 23, 1943 2,578,737 Powers Dec. 18, 1951 2,746,538 Johnson May 22, 1956 

